1. Field of the Invention
The present invention relates to security devices, and more particularly to a latching bar for securing bulkhead-type basement-entry doors.
2. Description of the Related Art
Homes with below-grade basements have traditionally been provided with some form of direct access to the outside, both to facilitate retrieval of large items (such as seasonal outdoor furniture, gardening equipment, sleds, bicycles, etc.) stored in the basement, as well as to limit foot traffic through first-floor rooms. The most common arrangement involves a pair of large, sloped "bulkhead" doors, installed against an exterior wall and covering a masonry enclosure extending away from the foundation. The enclosure includes a stairwell leading to the basement through a portal in the foundation. The portal ordinarily extends down to the basement floor, and is tall enough for convenient walk-through access to the stairwell. A slanted profile is preferred for the doors so that rain is shed instead of accumulating thereon.
Such an arrangement, indicated generally at reference numeral 10, appears in FIG. 1. A shell having a base 12 and sloping side walls 14 overlies a set of stairs leading to the basement. Covering the entryway defined by walls 14 is a face defined by a pair of overlapping leaf doors 18, 20 that rest against side pillars and a lintel that form, with base 12, a border frame 22. Both doors are affixed to walls 14 by oppositely disposed, concealed hinges (not shown), inaccessible from the exterior, that allow each door to swing open so as to expose the entryway. The outer door (door 20 in the representative illustration) is provided with a grip handle 24 that is lifted to open the door. Molded into door 20 is a recessed channel 26, which overlaps a flange (not shown) running along the length of door 18. In this way, the inner door 18 is prevented from opening unless outer door 20 is opened first. The flange also extends below the face of door 18 for reasons discussed below.
A typical latching mechanism for doors 18, 20 is also shown in FIG. 1. That mechanism consists of a retention bracket 30, welded to the inner face of door 20 near the edge that runs along door 18, and a steel rod 32 with 90.degree. bends that extend in opposite directions to form a pair of coplanar end segments 32a, 32b. Rod 32 extends movably through opposed apertures in bracket 30; a sufficent length of rod 32 intervenes between the two bends to permit rod 32 to slide back and forth. In a locked position (shown in FIG. 1), the center portion of rod 32 rests against the bottom edge of the flange beneath door 18 and end portion 32a binds against the far wall of the flange, while in a retracted position the entire rod 32 underlies door 20, freeing door 18 to open. To latch the doors, a user accesses the locking mechanism from the stairwell, slides rod 32 into the extended position and rotates end portion 32b so that it binds against the flange; this contact prevents door 20 from opening, while the upper edge of the flange, trapped within channel 26, prevents door 18 from opening. To unlatch the doors, the user flips end portion 32b to disengage end portion 32a and slides rod 32 to its retracted position.
While simple and easily operated, this latching mechanism may be defeated under some circumstances. Loose contact between rod end portion 32a and the flange of door 18 allows door 20 to be lifted beyond the upper edge of the flange to expose a gap between the doors. If the play between doors is sufficient, the exposed gap will admit a rod or other elongated instrument that can be used to flip and slide end portion 32b. Persistent jostling of loosely latched doors can also disengage end portion 32a from the flange of door 18.
Moreover, because rod 32 makes contact only with closely spaced-apart portions of doors 18 and 20, lifting of door 20 exerts substantial torque on the hinges of both doors. This further contributes to an intruder's ability to disrupt contact between rod 32 and door 18.